what is the important realizations and changes that occur once the men return to the year 2050 in the story the sound of thunder

2 or b: before

Explanation:

preposition: a word governing, and usually preceding, a noun or pronoun and expressing a relation to another word or element in the clause, as in “the man on the platform,” “she arrived after dinner,” “what did you do it for ?”.

Simple prepositions are words like at, for, in, off, on, over, and under. These common prepositions can be used to describe a location, time or place. Some examples of common prepositions used in sentences are: He sat on the chair.